CN1344065A - Piezoelectric device and its mfg. method - Google Patents

Abstract

To provide a piezoelectric device having a structure in which an external impact and a stress acting on a piezoelectric vibrating reed are strong, and an electrode side of a housing base and the piezoelectric vibrating reed can be electrically conducted satisfactorily, and a method for manufacturing the same. In the piezoelectric device having a structure in which a piezoelectric vibrating piece is bonded to an electrode 44 provided on a housing base 42, there is provided a piezoelectric device provided on the housing base 42 to conduct an excitation voltage through a conduction path 44b, and to assemble the above piezoelectric device. The assembly electrodes 44, 44 of the electric vibrating piece; and the conductive fixing members 41, 41 arranged on the surface of the above-mentioned assembly electrodes and made of a material with good close contact with the surface of the assembly electrodes. The above-mentioned piezoelectric vibrating piece 11 The conductive fixing member is bonded with a silicon-based conductive adhesive 15 , 15 .

Description

Piezoelectric device and manufacturing method thereof

technical field

The present invention relates to the structure and manufacturing method of a piezoelectric device such as a piezoelectric vibrator or a piezoelectric oscillator in which a piezoelectric vibrating piece is accommodated in a case.

Background technique

FIG. 8 is a diagram showing an example of a conventional piezoelectric vibrator, in which a cover is omitted for ease of understanding. 8( a ) is a plan view showing the state of the piezoelectric vibrator with the cover removed, and FIG. 8( b ) is a schematic cross-sectional view along line A-A showing the state with the cover removed.

In the figure, a piezoelectric vibrator 10 includes a box-shaped case base 12 in which a space 13 for accommodating a sheet-shaped piezoelectric vibrating piece 11 is formed. One end portion 11a of the piezoelectric vibrating piece 11 is bonded and fixed to gold-plated electrodes 14, 14 arranged on a stepped portion 19 provided in the space portion 13 through silicon-based conductive adhesives 15, 15. The two assembled electrodes, the other end 11b is a free end.

Here, as the piezoelectric vibrating piece 11, for example, crystal is used, electrodes (not shown) necessary for causing predetermined vibrations are formed on the surface, and an excitation voltage is applied to the crystal. Metal such as Kovar or ceramic such as alumina is used as a cover material (not shown) of package case base 12 .

Ceramics such as alumina are used as the material of the housing base 12. In the case of the figure, the second base material 17 with holes formed inside is superimposed on the first base material 16 in a flat plate shape, and then formed by overlapping. The third base material 18 has holes larger than the holes in the second base material. In addition, a seamed ring 18 a is disposed on the third base 18 . Therefore, the case base 12 forms a space portion 13 inside to accommodate the piezoelectric vibrating reed 11 , and also has a stepped portion 19 for joining the piezoelectric vibrating reed 11 .

Furthermore, the mounting electrodes 14, 14 on the surface of the stepped portion 19 are connected to the external terminal 14a exposed outside the case base 12 through the conduction path 14b in the layer structure in which the base materials are stacked. pass.

Therefore, the excitation voltage applied from the external electrode 14a is applied to the electrodes formed on the surface of the piezoelectric vibrating reed 11 through the mounting electrodes 14, 14, and the piezoelectric vibrating reed 11 is vibrated at a predetermined frequency.

FIG. 9 is a flowchart schematically showing the steps of manufacturing such a piezoelectric vibrator 10 .

In the figure, firstly, a housing base 12 is formed using a ceramic material such as alumina, and mounting electrodes 14 and 14 are formed corresponding to the piezoelectric vibrator 10 by, for example, electroplating.

At this time, as described above, in order to form the laminated structure of the housing base 12, green sheets of ceramic materials corresponding to the respective layers are formed on each layer, and these are stacked and then fired.

For example, FIG. 10 shows a green sheet corresponding to the second layer 17 of the base material in FIG. 8 , and a plurality of second layer base materials 17 are formed on one green sheet, which is still in an uncut state. For example, as shown in the figure, the mounting electrode 14 is formed on the second layer base material 17 by a method such as electrolytic plating in a state where the mounting electrode 14 is connected to the conductive path 14b (the conductive path 14b is sometimes formed across another layer). That is, after stacking and firing each layer, the seam ring 18a is welded, and electrolytic gold plating is performed on the external electrode 14a. In this case, as described above, the assembly electrode 14 is connected to the external electrode 14a through the conduction path 14b, so on the base layer of the tungsten metallization, gold (Au) is plated on the exposed part after overlapping, and the assembly electrode 14 is formed. and conduction path 14b.

FIG. 11 shows a housing base 12 in which base materials are stacked, FIG. 11( a ) is a plan view of the housing base 12 , and FIG. 11( b ) is a schematic cross-sectional view along line B-B.

As shown in the figure, if the third base material 18 is superimposed on the second base material 17, the conductive pattern 14b is almost hidden under the third base material 18, and two gold-plated patterns are exposed on the stepped portion 19. The electrodes 14, 14 are assembled.

Furthermore, after the seamed ring is welded to the third base material 18, the above-mentioned exposed mounting electrodes 14, 14 are plated with gold.

Therefore, gold is only plated on the exposed mounting electrodes 14, 14, and no gold is plated on the conductive pattern passing between the overlapping layers.

On the other hand, in FIG. 9, an excitation electrode or a connection electrode is formed on the piezoelectric vibrating piece 11 by vapor deposition, and silicon-based conductive adhesives 15, 15 are applied to the piezoelectric vibrating piece 11 mounted thereon. The electrodes 14, 14 are assembled (ST1).

Next, as shown in FIG. 8, the above-mentioned piezoelectric vibrating piece 11 is bonded and fixed on the assembly electrodes 14, 14 of the case base 12 in FIG. 8 through silicon series conductive adhesives 15, 15 (ST2).

Next, the case base 12 is placed in a thermosetting furnace not shown in the figure, and the silicon-based conductive adhesive 15, 15 is dried and cured (ST3). Then, the piezoelectric vibrating reed 11 is completely fixed on the assembly electrodes 14, 14 by the silicon series conductive adhesive 15, 15, and the excitation voltage is applied to the voltage from the external terminal 14a through the conduction path 14b and the assembly electrodes 14, 14. On the electric vibrating piece 11, while monitoring the vibration frequency, laser light is irradiated on the surface of the piezoelectric vibrating piece 11, and frequency adjustment is performed by reducing overlapping of electrodes (ST4).

Next, a cover body not shown in the figure is placed on the above-mentioned case base 12, and packaged, for example, by seam welding (ST5).

Through the above operations, the piezoelectric vibrator 10 is produced.

Such a process is also common to piezoelectric oscillators that are other piezoelectric devices. That is, since the piezoelectric oscillator is different from the piezoelectric vibrator, since the integrated circuit is mounted in the case base, its structure and process are somewhat different from the piezoelectric vibrator.

FIG. 12 is a view showing an example of a conventional piezoelectric oscillator, and the cover is omitted in the figure for ease of understanding. Fig. 12(a) is a plan view showing the piezoelectric vibrator with the cover removed, and Fig. 12(b) is a schematic cross-sectional view along line C-C showing the cover removed.

In these figures, the same structures as those of the piezoelectric vibrator shown in FIG. 10 are denoted by the same symbols, and description thereof will be omitted, and differences will be mainly described.

The piezoelectric vibrator 20 includes a box-shaped housing base 22 forming a space 23 for accommodating a sheet-shaped piezoelectric vibrating piece 11 . One end portion 11a of the piezoelectric vibrating piece 11 is bonded and fixed to gold-plated electrodes 14, 14 arranged on the stepped portion 19 provided in the space portion 23 through silicon-based conductive adhesives 15, 15. The two assembled electrodes, the other end 11b is a free end.

4 base materials 26, 27, 28, 29 made of ceramics are overlapped to form the shell base 22, the base material 26 at the bottom is a flat plate, and the base materials 27, 28, 29 overlapped on the top are successively increased by inner diameter. Large rings or frames of material are formed. Therefore, the housing base 22 forms a space portion 23 inside to accommodate the piezoelectric vibrating reed 11, and in addition to the stepped portion 19 for joining the piezoelectric vibrating reed 11, a second stepped portion 31 is provided at a lower position. .

Furthermore, the mounting electrodes 14 and 14 on the surface of the stepped portion 19 are connected to the integrated circuit 21 through the conduction path 14b passing through the layer structure in which the base material is stacked.

In addition, the integrated circuit 21 is mounted on the bottom inside the case base 22 , and a plurality of electrodes 24 formed by wire bonding the integrated circuit 21 and the gold wire 25 are formed on the stepped portion 31 . Here, since a part of the plurality of electrodes 24 is connected to the mount electrodes 14, 14 through the conduction path 14b, the mount electrodes 14, 14 are also plated with gold.

Fig. 13 shows the shell base 22 that each base material is stacked up, shows the structure of each electrode, Fig. 13 (a) is a plan view of the shell base 22, Fig. 13 (b) is a schematic sectional view along the D-D line .

As shown in the figure, mount electrodes 14 and 14 are formed on the stepped portion 19 , and a plurality of electrodes 24 formed by wire bonding are formed on the stepped portion 31 . In addition, electrodes 32 for mounting the integrated circuit 21 are provided on the inner bottom surface. The method of forming these electrodes is the same as that of the piezoelectric vibrator 10 .

Therefore, in the piezoelectric oscillator 20, the excitation voltage applied from the integrated circuit 21 is applied to the electrodes formed on the surface of the piezoelectric vibrating piece 11 through the mounting electrodes 14, 14, and the piezoelectric vibrating piece 11 is driven to the ground at a predetermined frequency. While vibrating, its output signal is input to the integrated circuit 21, and a predetermined frequency signal is taken out to the outside.

However, conventional piezoelectric devices have the following problems.

This problem is basically the same problem in the piezoelectric vibrator 10 and the piezoelectric oscillator 20 , so the piezoelectric vibrator 10 will be described.

8, FIG. 10, and FIG. 11, in the conventional piezoelectric vibrator 10, the mounting electrodes 14, 14 are connected to the external terminal 14a through the conduction path 14b (in the piezoelectric oscillator 20, for wire bonding on the electrode 24).

Here, these external terminals 14a or electrodes 24 are beneficial to be plated with gold like the above-mentioned structure in order to ensure the wettability of solder or soldering characteristics, etc., or to prevent oxidation, and the assembly electrodes 14, 14 connected to them are also gilded.

Then, the piezoelectric vibrating reed 11 is bonded to the mount electrodes 14, 14 with a silicon-based conductive adhesive 15, 15. Therefore, an excitation voltage is applied from the outside to supply the piezoelectric vibrating reed 11 .

Here, the reason why the silicon-based conductive adhesive 15 is used is as follows. That is, when the piezoelectric vibrator 10 or the piezoelectric oscillator 20 encounters a temperature change, if it is not a silicon series conductive adhesive, but an adhesive made of a hard resin such as an epoxy series or a polyimide series, When a difference in expansion or contraction occurs between the piezoelectric vibrating piece 11 and the housing base 12, the adhesive made of these hard resins cannot offset such a difference, so stress is applied to the piezoelectric vibrating piece 11, it often causes characteristic degradation such as frequency change or increase of CI (crystal impedance) value.

This point can be considered that when the piezoelectric vibrator 10 or the piezoelectric oscillator 20 is mounted on a mounting substrate or the like, deformation is caused by an external force, and when the deformation is transmitted to the piezoelectric vibrating piece 11 through an adhesive, it is also related to the piezoelectric vibrating piece 11. Same as above.

Therefore, as described above, the electrodes of the piezoelectric vibrating reed 11 are bonded to the mounting electrodes 14, 14 using relatively soft silicon-based conductive adhesives 15, 15. The silicon-based conductive adhesive is relatively soft and does not directly transmit external vibrations to the piezoelectric vibrating reed 11 and has a buffering effect. Since the silicon-based conductive adhesive contains silver fillers, conduction can be achieved.

However, there is a problem that the adhesion strength between the silicon-based conductive adhesive 15 and the gold component of the mount electrode is weak.

That is, gold is an inert metal that is not easily oxidized and has a weak bonding force with the resin used in the adhesive. In addition, the shrinkage force of the silicon-based conductive adhesive is small when it is hardened by heat (ST3 in Fig. 9). , Therefore, the contained silver filling component has a weak force to penetrate into the gold surface of the assembly electrode 14, which may cause poor conduction. In addition, the silicon-based conductive adhesive 15 forms a resin layer at the interface with gold, which also causes poor conduction.

Contents of the invention

The object of the present invention is to solve the above-mentioned problems, and to provide a piezoelectric device with a structure that has a large adaptability to external impact or stress acting on the piezoelectric vibrating piece, and can make the electrode side of the housing base and The piezoelectric vibrating piece conducts well.

According to the first aspect of the invention, the above objects can be achieved by a piezoelectric device having a structure in which a piezoelectric vibrating piece is joined to an electrode provided on a case base, the piezoelectric device There are: an assembly electrode arranged on the base of the above-mentioned housing, conducting the excitation voltage through a conduction path, and simultaneously assembling the above-mentioned piezoelectric vibrating piece; A conductive fixing member formed of a good material, the piezoelectric vibrating reed is bonded to the conductive fixing member with a silicon-based conductive adhesive.

If the structure of the first aspect is adopted, since a fixing member is provided on the surface of the mounting electrode of the housing base, a silicon-based conductive adhesive is used on the fixing member, and a silicon-based conductive adhesive is directly used on the electrode surface as in the past. Compared with the case of conductive adhesives, the adhesion strength is improved. Here, the fixing member is a member whose surface is mainly rough or finely uneven, or has at least a non-smooth surface, and means a member that enhances the fixing effect of the adhesive. Therefore, the silicon-based conductive adhesive does not adhere to the surface of the electrode with poor adhesion as in the past, but adheres to the surface of the fixing member having unevenness, for example. In this case, the silicone resin enters into the fine unevenness of the fixing member to improve the adhesion strength, and the silver filler contained also enters into the fine unevenness of the fixing member, so the conductivity is good.

A second aspect of the invention is characterized in that, in the structure of the first aspect, the fixing member is a conductive adhesive made of hard resin.

A third aspect of the invention is characterized in that in the structure of the second aspect, the fixing member is an epoxy-based or polyimide-based conductive adhesive.

According to the fourth aspect of the invention, the above-mentioned object can be achieved by a method of manufacturing a piezoelectric device, that is, a method of manufacturing a piezoelectric device including a step of bonding a piezoelectric vibrating reed to an electrode provided on a case base. Method, the bonding process of the above-mentioned piezoelectric vibrating reed is carried out as follows: a conductive adhesive in a molten state with high close contact performance with the electrode surface material is attached to the front end of the jig, and the jig is approximately perpendicular to the electrode surface. After moving, it touches on the surface of the assembly electrode, which is arranged on the above-mentioned shell base, conducts the excitation voltage through the conduction path, and secondly, makes the clamp leave along the above-mentioned vertical direction to form a fixing member on the surface of the assembly electrode, Then, the above-mentioned piezoelectric vibrating piece was placed on the fixing member using a silicon-based conductive adhesive, and the above-mentioned piezoelectric vibrating piece was bonded.

According to the fourth aspect of the invention, it is characterized in that in the bonding process of the piezoelectric vibrating reed in the manufacturing process of the piezoelectric device, first, a conductive adhesive having high close contact performance with the electrode surface material is attached to the jig. The tip moves the jig approximately vertically relative to the electrode surface and contacts the mounting electrode surface on the case base, and the paste-like conductive adhesive moves from the tip of the jig to the mounting electrode as the contact object. Thereafter, the jig is separated in the above-mentioned vertical direction, and a fixing member is formed on the surface on which the electrodes are mounted. That is, once the jig is separated in the above-mentioned vertical direction, the conductive adhesive with high close contact performance with the electrode surface material is pulled along the surface of the conductive adhesive along the direction of separation when the jig is separated. The direction of fine erection can constitute a fixing member formed with a rough surface or a fine concave-convex surface.

Therefore, the silicon-based conductive adhesive does not adhere to the surface of an electrode having poor adhesion as in the past, but adheres to, for example, the surface of a fixing member having unevenness. In this case, the silicone resin enters into the fine unevenness of the fixing member to improve the adhesion strength, and at the same time, the contained silver filler also enters into the fine unevenness of the fixing member, so the conduction performance is improved.

A fifth aspect of the invention is characterized in that, in the structure of the fourth aspect, the conductive adhesive attached to the jig is a conductive adhesive made of hard resin.

A sixth aspect of the invention is characterized in that, in the configuration of the fifth aspect, the conductive adhesive attached to the jig is an epoxy-based or polyimide-based conductive adhesive. A seventh aspect of the invention is characterized in that, in the configuration of the fifth aspect or the sixth aspect, the jig is a punching jig. Description of drawings:

Fig. 1 shows the piezoelectric vibrator of the preferred embodiment of the piezoelectric device of the present invention, Fig. 1 (a) is a plan view showing the state in which the cover body of the piezoelectric vibrator is removed, Fig. 1 (b) is a plan view showing the cover body A simplified cross-sectional view of the state along the E-E line after removal.

FIG. 2 is a flowchart schematically showing a manufacturing process of the piezoelectric vibrator in FIG. 1 .

FIG. 3 is an enlarged plan view showing the piezoelectric vibrator in FIG. 1 in the vicinity of mounting electrodes on the housing base.

FIG. 4 is an explanatory diagram illustrating a process of forming a fixing member on a mounting electrode of the piezoelectric vibrator in FIG. 1 .

Fig. 5 shows the state in which a fixing member is formed on the mounting electrode of the piezoelectric vibrator in Fig. 1, Fig. 5(a) shows the state of punching by a jig, and Fig. 5(b) is a partially enlarged cross-sectional view near the mounting electrode .

Fig. 6 shows the piezoelectric oscillator of the preferred second embodiment of the piezoelectric device of the present invention, Fig. 6 (a) is a plan view showing the state in which the cover of the piezoelectric oscillator is removed, Fig. 6 (b) It is a schematic cross-sectional view taken along the line F-F showing the state after the lid body is removed.

Fig. 7 is an enlarged plan view showing the vicinity of the mounting electrodes of the piezoelectric oscillator in Fig. 6 on the housing base.

Fig. 8 shows a conventional piezoelectric vibrator, Fig. 8(a) is a plan view showing the state of the piezoelectric vibrator after the cover body is removed, and Fig. 8(b) shows the state along the A-A line after the cover body is removed a brief cutaway diagram of the .

FIG. 9 is a flowchart schematically showing a manufacturing process of the piezoelectric oscillator shown in FIG. 8 .

10 is a plan view showing a green sheet corresponding to a second layer of the base material of the piezoelectric vibrator in FIG. 8 .

FIG. 11 shows a housing base in which the base materials of the piezoelectric vibrator are stacked. FIG. 11(a) is a plan view of the housing base, and FIG. 11(b) is a schematic cross-sectional view along line B-B.

Fig. 12 shows a conventional piezoelectric oscillator, Fig. 12(a) is a plan view showing a state in which the cover of the piezoelectric oscillator is removed, and Fig. 12(b) is a plan view showing a state in which the cover is removed A simplified sectional view of line C-C.

FIG. 13 shows a housing base in which the base materials of the piezoelectric oscillator in FIG. 12 are stacked, FIG. 13(a) is a plan view of the housing base, and FIG. 13(b) is a schematic cross-sectional view along line D-D.

Specific Embodiments of the Invention

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(first embodiment)

FIG. 1 shows a piezoelectric vibrator as an example of a piezoelectric device to which the present invention is applied.

In FIG. 1 , for ease of understanding, the cover body is omitted in the figure. 1( a ) is a plan view showing the state of the piezoelectric vibrator with the cover removed, and FIG. 1( b ) is a schematic cross-sectional view along line E-E showing the state of the piezoelectric vibrator with the cover removed.

In the figure, the piezoelectric vibrator 40 includes a box-shaped housing base 42 in which a space 43 for accommodating a sheet-shaped piezoelectric vibrating piece 11 is formed. One end portion 11a of the piezoelectric vibrating piece 11 is bonded and fixed to two assembly electrodes 44, 44 by means of silicon-based conductive adhesives 15, 15, and the electrodes 44, 44 are disposed on a stepped portion 49 provided in the space portion 43. , the other end 11b is a free end.

Here, as the piezoelectric vibrating piece 11, for example, crystal is used, electrodes (not shown) necessary for causing predetermined vibrations are formed on the surface, and an excitation voltage is applied to the crystal. Metal such as Kovar or ceramic such as alumina is used as a cover material (not shown) of package case base 42 .

Ceramics such as alumina are used as the material of the housing base 42. In the case of the figure, the second base material 47 with holes formed inside is superimposed on the flat first base material 46, and then formed by overlapping. A third base material 48 having holes larger than the holes in the second base material has a seam ring 48a superimposed thereon.

Furthermore, the mounting electrodes 44 and 44 on the surface of the stepped portion 49 are formed as a base by, for example, tungsten metallization, and an electrode film is formed on it, for example, of gold (Au). Then, as will be described later, fixed members 41, 41 provided on the gold surface are formed (see FIG. 1(a)).

In this embodiment, the fixing member 41, 41 is preferably used as the conductive adhesive made of the hard resin, for example, resin containing silver filler in epoxy series or polyimide series resin as a provision. Binder for conductive materials for conductive properties.

The mount electrodes 44 , 44 are connected to a conduction path 44 b passing through the laminated layer structure of the base material, and are connected to an external terminal 44 a exposed to the outside of the case base 42 .

Then, the piezoelectric vibrating reed 11 is mounted on the above-mentioned fixing members 41 , 41 provided on the surface of the mounting electrodes 44 , 44 through the silicon-based conductive adhesive 15 , 15 .

Here, since the silicon-based conductive adhesive 15 is used, when the piezoelectric vibrator 40 encounters a temperature change, when the difference in expansion or compression occurs between the piezoelectric vibrating piece 11 and the housing base 42, it can be properly offset. such a difference. Therefore, after a difference in expansion or compression occurs, stress is applied to the piezoelectric vibrating reed 11 without causing characteristic degradation such as a frequency change or an increase in CI (crystal impedance) value.

In addition, when the piezoelectric vibrator 40 is mounted on a mounting substrate or the like, it is also subjected to deformation caused by an external force. When the deformation is transmitted to the piezoelectric vibrating piece 11 through the adhesive, the deformation is not directly transmitted. Since the piezoelectric vibrating piece 11 is provided, the same stress as above can be prevented from acting on the piezoelectric vibrating piece 11 .

The silicon-based conductive adhesive 15, 15 is relatively soft, and has a buffering effect to prevent external vibration from being directly transmitted to the piezoelectric vibrating piece 11. The silicon-based conductive adhesive contains silver filler, so it can conduct immediately.

Therefore, the excitation voltage applied from the external terminal 44a as the external electrode is transmitted to the mounting electrodes 44, 44 through the conduction path 44b, and the excitation voltage is applied to the piezoelectric vibrating reed 11 from the silicon series conductive adhesive 15, 15. Therefore, the piezoelectric vibrating reed 11 is vibrated at a predetermined frequency.

FIG. 2 is a flowchart schematically showing the steps of manufacturing such a piezoelectric vibrator 40 .

In the figure, first, the case base 42 is formed from a ceramic material such as alumina, and mounting electrodes 44, 44, etc. are formed at positions corresponding to the piezoelectric vibrator 40 (ST11).

At this time, as described above, in order to make the case base 42 have a laminated structure, green sheets of piezoelectric materials corresponding to the respective layers are formed for each layer, stacked and fired.

Next, the fixing member 41 is formed on the surface where the electrodes 44, 44 are mounted. In addition, in the case of forming a piezoelectric oscillator in a piezoelectric device, an integrated circuit (IC) and other components are assembled (ST12). 3 is an enlarged partial plan view showing the vicinity of mount electrodes 44, 44 on case base 42. In this embodiment, fixing members 41, 41 are used for the central portion of the surface of each mount electrode 44, 44.

A method of forming the fixing members 41, 41 will be described in detail.

FIG. 4 is an explanatory diagram for explaining an actual process of forming the fixing members 41 , 41 . In the figure, the fixing members 41 , 41 are formed using a system including a material supply device 60 for fixing members and a dedicated jig 61 .

The material supply device 60 has a pedestal-shaped base 66 as a support, and a tank 65 as a storage tank opened at the upper side for storing the materials of the fixing members 41 , 41 is provided on the base 66 . That is, the material of the fixing members 41, 41 is a molten adhesive having a certain degree of viscosity. In the case of this embodiment, it is suitable to use gold (Au) as the surface material constituting the mounting electrodes 44, 44. Good adhesion material. Therefore, in this embodiment, the material of the fixing members 41, 41 is preferably a conductive adhesive made of hard resin, especially an epoxy series or polyimide series conductive adhesive. .

The roller 62 is disposed above the groove 65, and the roller 62 is rotatably supported in the direction of the arrow C at a position where it enters a part of the groove 65 from the upper part of the opening of the groove 65. The liquid level of the material inside.

Therefore, when the drum 62 is rotated, the material 41b is thinly attached to the surface of the drum 62 . Therefore, if the viscosity of the material is too high, the amount of material attached to the peripheral surface of the drum 62 will increase, so its viscosity is relatively low. In addition, at least the peripheral surface of the roller 62 is preferably not a completely smooth surface, for example, it is preferably formed of a permeable porous material, and the adhesive 41b with low viscosity is easy to adhere.

In addition, it is preferable to set the scraper 63 contacting the peripheral surface 64 of the drum 62 rotation. Since the drum 62 rotates in the direction of the arrow, after the material adheres to the peripheral surface 64 of the drum 62 from the groove 65, unnecessary excess material is scraped off. It is possible to deposit a desired thickness of material on the peripheral surface 64.

The special clamp 61 can at least move forward and backward along the direction shown by the arrow A in the figure, and can also move along the direction of the arrow B at the same time, and can be positioned above the roller 62 of the material supply device 60 and between the shell base 42 as the processed object. Mount electrodes 44, 44 and move between them. In order to realize such a structure, for example, a cantilever device or the like having a component suction jig of a mounter of an electronic component at the tip can be used.

In addition, the special jig 61 is, for example, in the shape shown in FIG. Low-viscosity adhesive 41b.

Construct material supply device 60 and special clamp 61 as above, for example as shown in Figure 4, when special clamp 61 is positioned at the top of material supply device 60, move up and down vertically, make its front end contact with the peripheral surface 64 of cylinder 62, adhesion bonding Agent 41b.

Next, move in the direction of the arrow B and be located above the housing base 42. Preferably, in this state, for example, control is performed based on information from an image processing device not shown in the figure, and the positions of the mounting electrodes 44, 44 are detected. , to move directly above it. From this state, the dedicated jig 61 is lowered in the direction of the arrow A, so that the tip to which the adhesive is attached is brought into vertical contact with the surface of the mounting electrode 44 . Next, the surface of the mounting electrode 44 rises in an almost vertical direction, away from the electrode.

In this way, the action or effect of the special fixture 61 generally has a stamping function, so that the conductive adhesive with a very thin thickness attached to the peripheral surface 64 of the drum 62 is attached to the front end of the special fixture 61, and secondly, the assembly electrode 44 The surfaces are stamped and contacted, the adhesive is attached to the surface of the assembly electrode 44, and the special jig 61 is separated vertically to form the fixing members 41, 41 as shown in FIG. That is, if the special jig 61 is separated in the vertical direction, when it is separated, along the direction of separation, the material on the surface of the conductive adhesive is finely erected in the direction in which it is pulled, and a rough surface can be formed. Or the fixing members 41, 41 of the fine concave-convex surface 41a.

Next, in a state where the adhesive 41b serving as the fixing members 41, 41 is applied to the surface on which the electrodes 44, 44 are mounted, the case base 42 is heated in a thermosetting furnace to dry and harden (ST13).

Accordingly, the adhesive is hardened on the surface where the electrodes 44, 44 are mounted. In this case, hard resin, especially epoxy series or polyimide series resin, has a strong and firm bonding force to the surface of mounting electrodes 44, 44, so that fixing member 41 can be firmly arranged on mounting electrodes 44, 44. superior.

Next, silicon-based conductive adhesives 15, 15 are coated on mounting electrodes 44, 44 of case base 42 in FIG. 1 or FIG. 3, respectively (ST14). Therefore, the state of Fig. 5(b) is obtained.

Next, the piezoelectric vibrating piece 11 is placed on the mounting electrodes 44, 44 coated with silicon series conductive adhesives 15, 15 (ST15), and the housing base 42 is placed in a thermosetting furnace not shown in the figure. Inside, bonding and fixing are performed by drying and curing the silicon-based conductive adhesive 15, 15 (ST16).

Then, when the piezoelectric vibrating reed 11 is completely fixed on the mounting electrodes 44, 44 with the silicon-based conductive adhesive 15, 15, the excitation voltage is transmitted to the mounting electrodes 44, 44 from the external terminal 44a through the conduction path 44b. 44. Apply the excitation voltage to the piezoelectric vibrating piece 11 from the mounting electrodes 44, 44, monitor its vibration frequency, and irradiate the laser light on the surface of the piezoelectric vibrating piece 11, and adjust the frequency by reducing the weight of the electrodes ( ST17).

Next, a cover body not shown in the figure is placed on the above-mentioned case base 42, and packaged, for example, by seam welding (ST18).

Through the above operations, the piezoelectric vibrator 40 is produced.

The first embodiment is constituted as described above. Since the piezoelectric vibrating reed 11 is bonded to the mounting electrodes 44, 44 through the fixing members 41, 41 by using the silicon-based conductive adhesive 15, 15, the silicon-based conductive adhesive 15 , 15 are not attached to the gold surface with poor adhesion as in the past, but enter and adhere to the fixing members 41, 41 with uneven or rough surfaces. In this case, the silicone resin enters the fine irregularities of the fixing members 41 , 41 to improve the adhesion strength, and the contained silver filler also enters the fine irregularities, so that the conductivity is good.

Here, since the piezoelectric vibrating reed 11 is bonded to the mounting electrodes 44 and 44 using silicon-based conductive adhesives 15 and 15, when the temperature of the piezoelectric vibrator 40 changes, the piezoelectric vibrating reed 11 and the housing base When differences in expansion or contraction occur between 42, such differences can be appropriately offset. Therefore, a difference in expansion or contraction occurs, and stress is applied to the piezoelectric vibrating reed 11, without causing characteristic deterioration such as a frequency change or an increase in CI (crystal impedance) value.

In addition, when the piezoelectric vibrator 40 is mounted on a mounting substrate or the like, it is subjected to deformation by an external force, and when the deformation is transmitted to the piezoelectric vibrating reed 11 through an adhesive, the deformation is not Since the stress is directly transmitted to the piezoelectric vibrating reed 11, the stress can be prevented from acting on the piezoelectric vibrating reed 11 in the same manner as above.

In addition, since the piezoelectric vibrating reed 11 and the mount electrodes 44, 44 are bonded using the silicon-based conductive adhesive 15, 15, the silicon-based conductive adhesive 15, 15 is also relatively soft after hardening, and can absorb external shocks. And the vibration is not transmitted to the piezoelectric vibrating piece 11, and has a strong impact-resistant structure.

Moreover, since the mounting electrodes 44, 44 and the silicon-based conductive adhesive 15, 15 are connected by the fixing members 41, 41 which are epoxy-based or polyimide-based conductive adhesives, it is possible to utilize hard resins reliably. The silicon-based conductive adhesive 15 and the mount electrodes 44, 44 are electrically connected to the ground. Therefore, the excitation voltage from the external terminal 44a can be reliably applied from the fixing members 41, 41 to the piezoelectric vibrating reed 11 through the conductive pattern 44b.

Next, the present invention is applied to the second embodiment of the piezoelectric oscillator.

The features of the manufacturing process of the first embodiment are almost common to the piezoelectric oscillator as another piezoelectric device. That is, unlike a piezoelectric vibrator, a piezoelectric vibrator incorporates an integrated circuit in a housing base, and therefore, related to this, its structure and process are slightly different from those of a piezoelectric vibrator.

(second embodiment)

FIG. 6 is a diagram showing an embodiment of a piezoelectric oscillator to which the present invention is applied, and the cover is omitted in the diagram for ease of understanding. 6( a ) is a plan view showing the state of the piezoelectric oscillator with the cover removed, and FIG. 6( b ) is a schematic cross-sectional view along line F-F showing the state of the piezoelectric oscillator with the cover removed.

In these figures, the same structures as those of the piezoelectric vibrator of the first embodiment or the piezoelectric oscillator in FIG. 12 are denoted by the same symbols, and description thereof will be omitted, and differences will be mainly described.

The piezoelectric oscillator 50 includes a box-shaped case base 52 in which a space 53 for accommodating a sheet-shaped piezoelectric vibrating piece 11 is formed. One end 11a of the piezoelectric vibrating piece 11 is bonded and fixed to two assembly electrodes 44, 44 by means of silicon-based conductive adhesives 15, 15, and the electrodes 44, 44 are disposed on a stepped portion 49 provided in the space portion 53. , the other end 11b is a free end.

The 4 base materials 56, 57, 58, 29 made of ceramics are overlapped, and the seam ring 59a is overlapped to form the housing base 52. The base material 56 at the bottom is a flat plate, and the base material 57 overlapped above , 58, 59 are formed of ring-shaped or frame-shaped materials whose inner diameters increase sequentially.

Therefore, the case base 52 forms a space portion 53 inside to accommodate the piezoelectric vibrating reed 11, and in addition to the stepped portion 49 for joining the piezoelectric vibrating reed 11, a second stepped portion 51 is provided at a lower position. .

Furthermore, the mount electrodes 44, 44 on the surface of the stepped portion 49 are structurally the same as those in Embodiment 1, and the mount electrodes 44, 44 are respectively connected to the conduction path 44b passing through the layer structure in which the base material is stacked, And it is connected to the electrode 54 of the case base 42 (to be described later).

As shown in the enlarged view in FIG. 7 , fixing members 41 , 41 are provided on the mounting electrodes 44 , 44 , and the forming method and function of the fixing members 41 , 41 are exactly the same as those of the first embodiment.

Therefore, the excitation voltage applied from the integrated circuit 21 (to be described later) is transmitted to the mounting electrodes 44, 44 through the conduction path 44b, and the excitation voltage is applied to the piezoelectric vibrating piece 11 from the silicon series conductive adhesive 15, 15. Therefore, the piezoelectric vibrating reed 11 is vibrated at a predetermined frequency.

In addition, the integrated circuit 21 is mounted on the inner bottom of the case base 52 , and the integrated circuit 21 and a plurality of electrodes 54 wire-bonded with gold wires 25 are formed on the stepped portion 51 . In addition, as shown in FIG. 7 , the electrodes 32 for mounting the integrated circuit 21 are provided on the inner bottom surface of the case base 52 . The method of forming these electrodes is the same as that of the piezoelectric vibrator 40 .

Therefore, in the piezoelectric oscillator 50, the excitation voltage applied from the integrated circuit 21 is applied to the electrodes formed on the surface of the piezoelectric vibrating piece 11 through the mounting electrodes 44, 44, and the piezoelectric vibrating piece 11 vibrates at a predetermined frequency. , and its output signal is input to the integrated circuit 21, and a predetermined frequency signal is taken out to the outside.

In addition, in the manufacturing process of the piezoelectric oscillator 50, only the mounting process of the integrated circuit 21 is added before ST12 of the manufacturing process of the piezoelectric vibrator 40 described with reference to FIG. 2, and the other processes are the same as in FIG.

As described above, the second embodiment has the same structure as the mount electrodes 44, 44 and the fixing members 41, 41, as well as the same joining structure of the piezoelectric vibrating reed 11, so it has the same operation and effect as the first embodiment.

The present invention is not limited to the above-described embodiments.

The present invention is not limited to piezoelectric vibrators and piezoelectric oscillators, and can be applied to various piezoelectric devices using piezoelectric vibrating reeds.

In addition, for example, the order of the manufacturing process can be changed, and each condition and each structure of the above-mentioned embodiments can be appropriately omitted or combined with each other.

As described above, according to the present invention, it is possible to provide a structure in which the impact from the outside and the stress acting on the piezoelectric vibrating reed are strong, and the electrode side of the case base and the piezoelectric vibrating reed can be well conducted. Piezoelectric device and method of manufacturing the same.

Claims (7)

1. A piezoelectric device having a structure in which a piezoelectric vibrating piece is joined to an electrode provided on a casing base, the piezoelectric device is characterized in that: An assembly electrode is provided on the above-mentioned case base, conducts the excitation voltage through the conduction path, and is equipped with the above-mentioned piezoelectric vibrating piece; and Arranged on the surface of the above-mentioned assembly electrode, using a conductive fixing member formed of a material that is in close contact with the surface of the assembly electrode, The above-mentioned piezoelectric vibrating piece is bonded to the conductive fixing member with a silicon-based conductive adhesive. 2. The piezoelectric device according to claim 1, wherein the fixing member is a conductive adhesive made of hard resin. 3. The piezoelectric device according to claim 2, wherein the fixing member is an epoxy-based or polyimide-based conductive adhesive. 4. A method of manufacturing a piezoelectric device, the method comprising a step of bonding a piezoelectric vibrating piece to an electrode provided on a housing base, characterized in that: The bonding process of the above-mentioned piezoelectric vibrating piece is carried out as follows: A conductive adhesive in a molten state that has high close contact performance with the electrode surface material is attached to the front end of the jig, and the jig is moved approximately vertically relative to the electrode surface to contact the surface of the assembled electrode. It is arranged on the base of the above-mentioned housing, conducts the excitation voltage through the conduction path, Next, the jig is separated in the above-mentioned vertical direction to form a fixing member on the surface on which the electrode is mounted, Then, the above-mentioned piezoelectric vibrating piece was placed on the fixing member using a silicon-based conductive adhesive, and the above-mentioned piezoelectric vibrating piece was bonded. 5. The piezoelectric device according to claim 4, wherein the conductive adhesive attached to the jig is a conductive adhesive made of hard resin. 6. The piezoelectric device according to claim 5, wherein the conductive adhesive attached to the jig is epoxy-based or polyimide-based conductive adhesive. 7. The piezoelectric device according to any one of claims 4 to 6, wherein the jig is a punching jig.

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